Known solutions for selecting an endoprosthesis and determining its position prior to a surgical intervention use a standard VDU workstation and fitting software in order to position, by mouse input, a graphical representation of endoprostheses in, for example, a relevant slice of a CT dataset or an X-ray photograph.
In clinical practice, the “fitting” of an endoprosthesis using the computer mouse is often experienced as unergonomic and laborious by physicians. They therefore use both a copy of the electronic image data on an X-ray film and templates of the different endoprostheses available in order to select a suitable endoprosthesis by manually moving different templates around on the X-ray film. This method will be referred to hereinafter as the “X-ray film/template technique”. Although the decision concerning the selection of a particular endoprosthesis is recorded in a diagnostic findings report, the exact position of the endoprosthesis is not transferred to an X-ray image dataset in electronic form.
In “S. Izadi et al., Going Beyond the Display: A Surface Technology with an Electronically Switchable Diffuser; in Proceedings of User Interface Software and Technology 2008 (ACM UIST 2008)”, the innovative “Second Light” screen display system is presented. “Second Light” uses an interactive display surface technology based on a switchable (rear) projection screen which can be made diffuse or transparent under electronic control.
A first projection screen is formed by the immovable surface of a housing and is designed as a diffuser which can be electrically switched to the modes “diffuse” or “clear” and is therefore used either as a projection screen or lets light pass through it. If switching between the two modes takes place at a high frequency that is imperceptible to the human eye (e.g. 100 Hz), during the clear phase an image can be projected through the first projection screen onto a second movable (rear) projection screen located above the first projection screen. The alternating transparency of the first projection screen also enables the manipulations (displacements, rotations) on the movable second projection screen to be tracked using a camera located below the first projection screen, and image processing software. Alternatively, manipulations (displacements, rotations) of the second projection screen could also be tracked by making the first projection screen touch-sensitive.